This invention relates to systems and methods for processing and collecting blood, blood constituents, or other suspensions of cellular material.
Today people routinely separate whole blood, usually by centrifugation, into its various therapeutic components, such as red blood cells, platelets, and plasma.
Conventional blood processing methods use durable centrifuge equipment in association with single use, sterile processing systems, typically made of plastic. The operator loads the disposable systems upon the centrifuge before processing and removes them afterwards.
Conventional blood centrifuges are of a size that does not permit easy transport between collection sites. Furthermore, loading and unloading operations can sometimes be time consuming and tedious.
In addition, a need exists for further improved systems and methods for collecting blood components in a way that lends itself to use in high volume, on line blood collection environments, where higher yields of critically needed cellular blood components, like plasma, red blood cells, and platelets, can be realized in reasonable short processing times.
The operational and performance demands upon such fluid processing systems become more complex and sophisticated, even as the demand for smaller and more portable systems intensifies. The need therefore exists for automated blood processing controllers that can gather and generate more detailed information and control signals to aid the operator in maximizing processing and separation efficiencies.
The invention provides systems and methods for processing blood and blood constituents that lend themselves to portable, flexible processing platforms equipped with straightforward and accurate control functions.
More particularly, the invention provides fluid pressure actuated blood pumping systems and methods, which achieve continuous inflow and pulsatile outflow conditions.
According to one aspect of the invention, blood processing systems and related methods placing first and second fluid pressure actuated pump stations in in-line communication between a source and a destination. The systems and methods apply fluid pressure pump strokes to the first and second pump stations to convey fluid from the source to the destination. The systems and methods switch between a first flow mode and a second flow mode. In the first flow mode, the pump strokes draw a fluid volume into the first pump station from the source and expel a fluid volume from the second pump station to the destination. In the second flow mode, the pump strokes draw a fluid volume into the second pump station from the source and expel a fluid volume from the first pump station to the destination. The systems and methods synchronize the pump strokes so that fluid flow from the source is essentially continuous while fluid flow to the destination is pulsatile.
Either the source or the destination can comprise a venipuncture, or a blood collection container, or a reservoir, or a source of processing fluid. The destination can also communicate with a blood processing device.
In one embodiment, the systems and methods synchronize the pump strokes so that an expel pump stroke expels a fluid volume from a respective one of the pump stations through the application of positive fluid pressure and a draw pump stroke draws a fluid volume into a respective other one of the pump stations through the application of negative fluid pressure.
In one embodiment, the draw pump stroke has a duration longer than the expel pump stroke. In this arrangement, an expel pump stroke for a respective one of the pump stations occurs at a beginning of a draw pump stroke for a respective other one of the pump stations.
In one embodiment, the expel pump stroke applies positive pneumatic pressure and the draw pump applies negative pneumatic pressure.